The disclosure relates to polyestercarbonates and more particularly, to polyestercarbonates based on bisphenols derived from cyclic monoterpene precursors as one of the building blocks. The disclosure also relates to melt transesterification polymerization methods for making the polyestercarbonates and to methods for making such articles from the polyestercarbonates.
Polycarbonate homopolymers are widely used in a variety of applications by virtue of their excellent physical properties, such as impact resistance, mechanical characteristics, transparency, and the like. Bisphenol A (BPA) polycarbonate, the industry benchmark material, by virtue of its low cost, good transparency, and mechanical properties has served as the substrate of choice for optical data storage media such as compact disk and digital versatile disk (DVD). However, the need to store greater amounts of information on individual disks has resulted in newer techniques for high-density data storage, based on multiple information layers and shorter wavelength lasers, such as high density DVD (HDDVD), digital video recordable (DVR), DVD-recordable (DVDxe2x88x92R and DVD+R), and DVD-rewritable (DVDxe2x88x92RW and DVD+RW) formats. The transparent plastic layer that forms the non-interfering shielding on such optical media disks requires more demanding material specifications, such as high transparency, heat resistance, low water absorption, ductility and fewer particulates that standard BPA homopolycarbonate cannot meet. Therefore, polyestercarbonates have been studied for their utility as a more effective material for optical media applications, such as data storage and retrieval.
One of the critical properties that influence the efficacy of a given material for higher data storage density is the spacing between the pits and grooves on the substrate material. Since data is stored in these pits and grooves, the flatness of the disk is necessary to prevent loss of information. It is known that excessive moisture absorption by the disk results in skewing of the disk or the films that form the disk, which in turn leads to reduced reliability. This skewing, hereinafter referred to as dimensional stability, will result in data being stored or read inaccurately by the laser beam. Since the bulk of the disk is generally comprised of polymer material, the flatness of the disk depends on the low water absorption of the polymeric material. For example, a film produced from conventional BPA polycarbonate often exhibits warp due to absorption of ambient moisture. The dimensional stability is a function of, among other factors, the amount of ambient moisture present as well as the rate of moisture absorption. In addition to possessing optimum dimensional stability, a satisfactory material for such advanced format optical disks should also exhibit optimum replication and cycle time vis-à-vis the conditions for manufacturing conventional optical disks, such as compact disks. In order to produce high quality disks through injection molding, the polymer should also be easily processible, that is, exhibit good flow. Therefore there is a continued need for developing new materials as suitable substrates that would serve these advanced data storage formats. Suitable materials for high-density storage formats should satisfactorily address the critical requirement of dimensional stability, in addition to replication and cycle time, without compromising on any of the other desirable characteristics that BPA homopolycarbonate already possesses.
A polyestercarbonate comprising structural units derived from at least one bisphenol of the formulas: 
wherein each A1 is independently a divalent substituted or unsubstituted aromatic radical; at least one aromatic dihydroxy compound of the formula:
HOxe2x80x94A2xe2x80x94OH
wherein A2 is selected from divalent substituted and unsubstituted aromatic radicals; at least one dicarboxylic acid diester of the formula: 
wherein Y is a C1-C40 linear or branched divalent hydrocarbyl radical, and Rxe2x80x2 is a C7-C12 aryl or alkaryl radical; and at least one carbonic acid diester of the formula (ZO)2Cxe2x95x90O, wherein each Z is independently an unsubstituted or substituted alkyl radical, or an unsubstituted or substituted aryl radical.
In another embodiment, the polyestercarbonate comprises structural units derived from at least one bisphenol of the formulas: 
at least one aromatic dihydroxy compound comonomer selected from the group consisting of resorcinol, bisphenol A, 4,4xe2x80x2-(1-decylidene)-bisphenol, 2,2-bis(3-sec-butyl-4-hydroxyphenyl)propane and mixtures thereof; at least one dicarboxylic acid diester of the formula 
wherein Y is a linear divalent hydrocarbyl group of the formula (CH2)n, wherein n has values in the range from about 4 to about 18, and Rxe2x80x2 is phenyl; and diphenyl carbonate, wherein the polyestercarbonate has a glass transition temperature of at least about 100xc2x0 C.; a weight average molecular weight of at least about 5,000; and a dimensional stability as measured by percentage elongation of less than about 0.05% relative to its initial length following exposure to air with a relative humidity of about 100%, at a temperature of about 23xc2x0 C., and for a duration of about 3 hours.
A melt transesterification polymerization method for producing a polyestercarbonate is disclosed herein. The method comprises combining a catalyst and a reactant composition to form a reaction mixture; and mixing the reaction mixture under reactive conditions for a time period to produce a polyestercarbonate product, wherein the reactant composition comprises a carbonic acid diester of the formula (ZO)2Cxe2x95x90O, where each Z is independently an unsubstituted or substituted alkyl radical, or an unsubstituted or substituted aryl radical; at least one bisphenol of the formula: 
wherein each A1 is independently a substituted or unsubstituted divalent aromatic radical; at least one aromatic dihydroxy compound comonomer selected from the group consisting of
HOxe2x80x94A2xe2x80x94OH
wherein A2 is selected from divalent substituted or unsubstituted aromatic radicals; and at least one dicarboxylic acid diester selected from the group consisting of 
wherein Y is a C1-C40 linear or branched divalent hydrocarbyl radical, and Rxe2x80x2 is a C7-C12 aryl or alkaryl radical.
In another embodiment, the method for producing a polyestercarbonate by a melt transesterification polymerization method comprises combining a catalyst comprising at least one of sodium hydroxide or tetramethylammonium hydroxide, and a reactant composition to form a,reaction mixture; and mixing the reaction mixture under reactive conditions for a time period to produce a polyestercarbonate product, wherein the reactant composition comprises a diphenyl carbonate; at least one bisphenol of the formulas: 
at least one aromatic dihydroxy compound comonomer selected from the group consisting of resorcinol, bisphenol A, 4,4xe2x80x2-(1-decylidene)-bisphenol, 2,2-bis(3-sec-butyl-4-hydroxyphenyl)propane and mixtures thereof; and at least one dicarboxylic acid diester selected from the group consisting of 
wherein Y is a linear divalent hydrocarbyl group of the formula (CH2)n, wherein n has values in the range from about 4 to about 18, and Rxe2x80x2 is phenyl.
The embodiments of the present disclosure have many advantages, including the ability to manufacture the above mentioned polyestercarbonates in a cost effective, environmentally acceptable manner, and for fabricating articles and films suitable for high heat, and optical data storage/retrieval applications.
Disclosed herein are polyestercarbonates that are suitable for high density storage formats. The polyestercarbonates are preferably formed by melt transesterification (i.e., a melt method) of bisphenol compound, an aromatic dihydroxy compound comonomer, a dicarboxylic acid compound, and a carbonic acid diester compound.
Preferably, the bisphenol compounds are derived from cyclic monoterpene precursors, and more preferably comprise those having formulas (I) or (II): 
wherein A1 is a substituted or unsubstituted divalent aromatic radical.
In one embodiment, the bisphenols derived from cyclic monoterpene precursors comprise bis(hydroxyaryl)cyclohexanes such as structures (III) and (IV) as shown below: 
The above bisphenols can be readily prepared using procedures described, for example, in U.S. Pat. No. 5,480,959.
Aromatic dihydroxy compound comonomers that can be employed in the disclosure comprise those of the general formula (V):
HOxe2x80x94A2xe2x80x94OH,xe2x80x83xe2x80x83(V)
wherein A2 is a divalent aromatic radical.
In some embodiments, A2 has the structure of formula (VI): 
wherein G1 represents an aromatic group, such as phenylene, biphenylene, naphthylene, etc. E may be an alkylene or alkylidene group such as methylene, ethylene, ethylidene, propylene, propylidene, isopropylidene, butylene, butylidene, isobutylidene, amylene, amylidene, isoamylidene, etc. and may consist of two or more alkylene or alkylidene groups connected by a moiety different from alkylene or alkylidene, such as an aromatic linkage; a tertiary amino linkage; an ether linkage; a carbonyl linkage; a silicon-containing linkage; or a sulfur-containing linkage such as sulfide, sulfoxide, sulfone, etc.; or a phosphorus-containing linkage such as phosphinyl, phosphonyl, etc. In addition, E may be a cycloaliphatic group. R1 represents hydrogen or a monovalent hydrocarbon group such as alkyl, aryl, aralkyl, alkaryl, or cycloalkyl. Y1 may be an inorganic atom such as halogen (fluorine, bromine, chlorine, iodine); an inorganic group such as nitro; an organic group such as alkenyl, allyl, or R1 above, or an oxy group such as OR; it being only necessary that Y1 be inert to and unaffected by the reactants and reaction conditions used to prepare the polymer. The letter m represents any integer from and including zero through the number of positions on G1 available for substitution; p represents an integer from and including zero through the number of positions on E available for substitution; xe2x80x9ctxe2x80x9d represents an integer equal to at least one; xe2x80x9csxe2x80x9d is either zero or one; and xe2x80x9cuxe2x80x9d represents any integer including zero.
Suitable examples of E include cyclopentylidene, cyclohexylidene, 3,3,5-trimethylcyclohexylidene, methylcyclohexylidene, 2-[2.2.1]-bicycloheptylidene, neopentylidene, cyclopentadecylidene, cyclododecylidene, adamantylidene, etc.); a sulfur-containing linkage, such as sulfide, sulfoxide or sulfone; a phosphorus-containing linkage, such as phosphinyl, phosphonyl; an ether linkage; a carbonyl group; a tertiary nitrogen group; or a silicon-containing linkage such as silane or siloxy.
In the aromatic dihydroxy comonomer compound (V) in which A2 is represented by formula (VI) above, when more than one Y1 substituent is present, they may be the same or different. The same holds true for the R1 substituent. Where s is zero in formula (VI) and u is not zero, the aromatic rings are directly joined with no intervening alkylidene or other bridge. The positions of the hydroxyl groups and Y1 on the aromatic nuclear residues G1 can be varied in the ortho, meta, or para positions and the groupings can be in vicinal, asymmetrical or symmetrical relationship, where two or more ring carbon atoms of the hydrocarbon residue are substituted with Y1 and hydroxyl groups. In some particular embodiments, the parameters xe2x80x9ctxe2x80x9d, xe2x80x9csxe2x80x9d, and xe2x80x9cuxe2x80x9d are each one; both G1 radicals are unsubstituted phenylene radicals; and E is an alkylidene group such as isopropylidene. In particular embodiments, both G1 radicals are p-phenylene, although both may be o- or m-phenylene or one o- or m-phenylene and the other p-phenylene.
Some illustrative, non-limiting examples of aromatic dihydroxy comonomer compounds of formula (V) include the dihydroxy-substituted aromatic hydrocarbons disclosed by name or formula (generic or specific) in U.S. Pat. No. 4,217,438. Some particular examples of aromatic dihydroxy compound comonomers include 4,4xe2x80x2-(3,3,5-trimethylcyclohexylidene)diphenol; 4,4xe2x80x2-bis(3,5-dimethyl)diphenol, 1,1-bis(4-hydroxy-3-methylphenyl)cyclohexane; 4,4-bis(4-hydroxyphenyl)heptane; 2,4-dihydroxydiphenylmethane; bis(2-hydroxyphenyl)methane; bis(4-hydroxyphenyl) methane; bis(4-hydroxy-5-nitrophenyl)methane; bis(4-hydroxy-2,6-dimethyl-3-methoxyphenyl)methane; 1,1-bis(4-hydroxyphenyl)ethane; 1,1-bis(4-hydroxy-2-chlorophenyl)ethane; 2,2-bis(4-hydroxyphenyl)propane (commonly known as bisphenol A); 2,2-bis(3-phenyl-4-hydroxyphenyl)propane; 2,2-bis(4-hydroxy-3-methylphenyl)propane; 2,2-bis(4-hydroxy-3-ethylphenyl)propane; 2,2-bis(4-hydroxy-3-isopropylphenyl)propane; 2,2-bis(4-hydroxy-3,5-dimethylphenyl) propane; 2,2-bis(3,5,3xe2x80x2,5xe2x80x2-tetrachloro-4,4xe2x80x2-dihydroxyphenyl)propane; bis(4-hydroxyphenyl)cyclohexylmethane; 2,2-bis(4-hydroxyphenyl)-1-phenylpropane; 2,4xe2x80x2-dihydroxyphenyl sulfone; 2,6-dihydroxy naphthalene; hydroquinone; resorcinol; and C1-3 alkyl-substituted resorcinols.
Suitable aromatic dihydroxy comonomer compounds also include those containing indane structural units such as those represented below by formulas (VII) and (VIII) as shown below. Formula (VII) represents 3-(4-hydroxyphenyl)-1,1,3-trimethylindan-5-ol, and formula (VIII) represents 1-(4-hydroxyphenyl)-1,3,3-trimethylindan-5-ol. 
Also included among suitable aromatic dihydroxy compound comonomers are the 2,2,2xe2x80x2,2xe2x80x2-tetrahydro-1,1xe2x80x2-spirodiols having formula (IX) as follows: 
wherein each R6 is independently selected from monovalent hydrocarbon radicals halogen radicals; wherein each R7, R8, R9, and R10 is independently C1-6 alkyl; wherein each R11 and R12 is independently H or C1-2 alkyl; and wherein each n is independently selected from positive integers having a value of from 0 to 3 inclusive. In a particular embodiment, the 2,2,2xe2x80x2,2xe2x80x2-tetrahydro-1,1xe2x80x2-spiro-diol is 2,2,2xe2x80x2,2xe2x80x2-tetrahydro-3,3,3xe2x80x2,3xe2x80x2-tetramethyl-1,1xe2x80x2-spirobi[1H-indene]-6,6xe2x80x2-diol (sometimes known as xe2x80x9cSBIxe2x80x9d).
The term xe2x80x9calkylxe2x80x9d as used in the various embodiments of the present disclosure is intended to designate straight chain alkyl, branched alkyl, aralkyl, cycloalkyl, and bicycloalkyl radicals. In various embodiments, straight chain and branched alkyl radicals, unless otherwise specified are those containing from 1 to about 40 carbon atoms, and include as illustrative non-limiting examples methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tertiary-butyl, pentyl, neopentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl and dodecyl. In various embodiments, cycloalkyl radicals represented are those containing from 3 to about 12 ring carbon atoms. Some illustrative non-limiting examples of these cycloalkyl radicals include cyclobutyl, cyclopentyl, cyclohexyl, methylcyclohexyl, and cycloheptyl. In various embodiments, aralkyl radicals are those containing from 7 to 14 carbon atoms; these include, but are not limited to, benzyl, phenylbutyl, phenylpropyl, and phenylethyl. In various embodiments, aromatic radicals used in the present disclosure are intended to designate monocyclic or polycyclic moieties containing from 6 to about 12 ring carbon atoms. These aryl groups may also contain one or more halogen atoms or alkyl groups substituted on the ring carbons. In most embodiments, any substituent present is not in a ring position that would prevent an appropriate aromatic radical, such as in a phenolic aromatic radical, from reacting with an appropriate olefinic group, such as in a monoterpene. Some illustrative non-limiting examples of these aromatic radicals include phenyl, halophenyl, biphenyl, and naphthyl. In another embodiment, aromatic radicals used in the present disclosure are intended to designate aralkyl radicals containing from 7 to 14 carbon atoms.
The polyestercarbonates also comprise structural units derived from at least one dicarboxylic acid diester of the general formula (X) 
wherein Y is a C1-C40 linear or branched divalent hydrocarbyl radical, and Rxe2x80x2 is a C1-C12 aryl or alkaryl radical.
The structural units derived from dicarboxylic acid diester moieties may be unsubstituted or substituted. The substituents if present, are in some embodiments, C1-12 alkyl groups. In one embodiment, a suitable alkyl group is methyl. Suitable halogen substituents comprise bromo, chloro, and fluoro. Dicarboxylic acid diester moieties containing a mixture of alkyl and halogen substituents are also suitable. In other embodiments, dicarboxylic acid diesters comprise alkylene dicarboxylic acid diesters, and in a particular embodiment, alkylene dicarboxylic acid diaryl esters, wherein alkylene groups comprise, in various embodiments, C3-20 straight chain alkylene, C3-20 branched alkylene, or C4-20 cyclo- or bicycloalkylene group. In a particular embodiment, the dicarboxylic acid diester is diphenyl dodecanedioate. In other particular embodiments, dicarboxylic acid diester comprises diphenyl decanedioate, diphenyl tetradecanedioate, diphenyl hexadecanedioate, diphenyl octadecanedioate, and combinations comprising at least one of the foregoing dicarboxylic acid diester moieties in amounts to provide proportions of structural units as described hereinabove.
In various embodiments, diaryl esters comprise diphenyl esters and are derived from phenol. In other embodiments, diaryl esters comprise those derived from monohydroxy aromatic compounds comprising at least one electron withdrawing group ortho, meta, or para to the oxygen substituent of the monohydroxy moiety. In another embodiment, diaryl esters comprise those derived from monohydroxy aromatic compounds comprising at least one electron-withdrawing group ortho or para to the oxygen substituent of the monohydroxy moiety. In another embodiment, diaryl esters comprise those derived from monohydroxy aromatic compounds comprising at least one electron-withdrawing group ortho or para to the oxygen substituent of the monohydroxy moiety selected from the group consisting of o-carboalkoxy, o-carboaryloxy, carboaryl, halo, cyano, and nitro, and mixtures thereof. In another embodiment, diaryl esters comprise those derived from monohydroxy aromatic compounds selected from the group consisting of o-carbomethoxyphenol, o-carbomethoxymethylphenol, o-carboethoxyphenol, o-carbopropoxyphenol, o-chlorophenol, o-carbophenylphenol, o-carbophenoxyphenol, o-carbobenzoxyphenol, and o-nitrophenol.
In another embodiment, the dicarboxylic acid diester also comprises one or a combination of two or more dicarboxylic acid and dicarboxylic acid monoester of the formula (XI): 
wherein Y is a C1-C40 linear or branched divalent hydrocarbyl radical, and Rxe2x80x2 is hydrogen, C7-C12 aryl or alkaryl radical. The dicarboxylic acids or the dicarboxylic acid monoesters are present in an amount ranging from about 0 to about 50 mole percent in one embodiment, and in an amount ranging from about 0 to about 30 mole percent in another embodiment, relative to the amount of the dicarboxylic acid diester. When such dicarboxylic acids and/or the dicarboxylic acid monoester are used, more carbonic acid diester is required to convert the carboxylic acid group into the ester group. Examples of the dicarboxylic acids and dicarboxylic acid monoesters include: sebacic acid, monophenyl sebacate, dodecanedioic acid, and monophenyl dodecanedioate, etc.
In other embodiments, the polyestercarbonates described herein have a weight average molecular weight of at least about 5,000, a glass transition temperature of at least about 100xc2x0 C., and a dimensional stability in films comprising said polyestercarbonate, as measured by percentage elongation of less than about 0.05% relative to its initial length following exposure to nitrogen with a relative humidity of about 100 at a temperature of about 23xc2x0 C. and for a duration of about 3 hours.
In some embodiments of the disclosure, the polyestercarbonates comprise at least one carbonate structural unit selected from the group consisting of formulas (XII) and (XIII): 
wherein A1 is a substituted or unsubstituted divalent aromatic radical.
In other embodiments, the polyestercarbonates comprise at least one carbonate structural unit selected from the group shown in formula (XIV): 
wherein A2 is a divalent aromatic radical.
In other embodiments, the polyestercarbonates comprise at least one structural unit selected from the group shown in formula (XV): 
wherein Y is independently a C1-C40 linear or branched divalent hydrocarbyl radical.
Various embodiments of the disclosure also comprise at least one carbonic acid diester of formula (XVI):
(ZO)2Cxe2x95x90O,xe2x80x83xe2x80x83(XVI)
wherein each Z is independently an unsubstituted or substituted alkyl radical, or an unsubstituted or substituted aryl radical. Substituents on Z, when present, may include, but are not limited to, one or more of alkyl, halogen, chloro, bromo, fluoro, nitro, alkoxy, alkoxycarbonyl, methoxycarbonyl, ethoxycarbonyl, and cyano. Some particular examples of the carbonic acid diester that can be used in the present disclosure include diaryl carbonates, dialkyl carbonates and mixed aryl-alkyl carbonates such as diphenyl carbonate, bis(2,4-dichlorophenyl) carbonate, bis(2,4,5-trichlorophenyl) carbonate, bis(2-cyanophenyl) carbonate, bis(o-nitrophenyl) carbonate, (o-carbomethoxyphenyl)carbonate; (o-carboethoxyphenyl)carbonate, ditolyl carbonate, m-cresyl carbonate, dinaphthyl carbonate, bis(diphenyl) carbonate, diethyl carbonate, dimethyl carbonate, dibutyl carbonate and dicyclohexyl carbonate, and combinations of two or more thereof. Of these, diphenyl carbonate is often used in particular embodiments. In some embodiments, if two or more of these compounds are utilized, one is diphenyl carbonate.
A method for producing the polyestercarbonate by a melt transesterification polymerization includes combining a catalyst and a reactant composition to form a reaction mixture; and mixing the reaction mixture under reactive conditions for a time period to produce a polyestercarbonate product. The reactant composition comprises the carbonic acid diester of formula (XV) (ZO)2Cxe2x95x90O, wherein each Z is independently an unsubstituted or substituted alkyl radical, or an unsubstituted or substituted aryl radical; at least one bisphenol of the formulas (I) or (II): 
wherein each A1 is independently a substituted or unsubstituted divalent aromatic radical; at least one aromatic dihydroxy compound comonomer selected from the group consisting of formula (V)
HOxe2x80x94A2xe2x80x94OH,xe2x80x83xe2x80x83(V)
wherein A2 is selected from divalent substituted or unsubstituted aromatic radicals; and at least one dicarboxylic acid diester selected from the group consisting of formula (X) 
wherein Y is a C1-C40 linear or branched divalent hydrocarbyl radical, and Rxe2x80x2 is a C7-C12 aryl or alkaryl radical.
In particular embodiments of the method, the bisphenol comprises at least one bis (hydroxyaryl)cyclohexane of formulas (III) or (IV) or combinations comprising at least one of the foregoing bisphenols. 
In the preparation of the polyestercarbonates, the aromatic dihydroxy compound comonomers described above may be used alone, or as mixtures of two or more different aromatic dihydroxy compound comonomers. In one particular embodiment, suitable aromatic dihydroxy compound comonomers for the preparation of a polyestercarbonate are 2,2-bis(4-hydroxyphenyl)propane (commonly known as bisphenol A or xe2x80x9cBPAxe2x80x9d), resorcinol, 4,4xe2x80x2-(1-decylidene)-bisphenol (sometimes referred to hereinafter as xe2x80x9cbispdedxe2x80x9d) and 2,2-bis(3-sec-butyl-4-hydroxyphenyl)propane (sometimes referred to hereinafter as xe2x80x9cs-BPAxe2x80x9d), or combinations comprising at least one of the foregoing aromatic dihydroxy compounds.
In some embodiments, the polyestercarbonates are prepared using at least one dicarboxylic acid diester selected from the group consisting of formula (X) 
wherein Y is a linear alkylidene group having the formula (CH2)n, wherein n has values of about 4 to about 18, and Rxe2x80x2 is a phenyl radical. In a particular embodiment, n has the value of about 12, and Rxe2x80x2 is a phenyl radical.
Alternatively, the dicarboxylic acid diester comprises one or a combination of two or more dicarboxylic acid and dicarboxylic acid monoester of the formula (XI): 
wherein Y is a C1-C40 linear or branched divalent hydrocarbyl radical, and Rxe2x80x2 is hydrogen, C7-C12 aryl or alkaryl radical.
During the manufacture of the polyestercarbonates by the melt transesterification method, the amount of the above types of carbonic acid diesters and the dicarboxylic acid diesters are in some embodiments, in an amount of 0.95 to 1.30 moles, and in other embodiments, in an amount of 1.05 to 1.1 5 moles, based on one mole of the bisphenol and aromatic dihydroxy comonomer compounds described above.
Catalysts that can be used for the melt transesterification polymerization include all those known to be effective for such polymerization. In various embodiments such catalysts are selected from the group consisting of alkali metal compounds, alkaline earth metal compounds, tetraorganoammonium compounds, and tetraorganophosphonium compounds, combinations comprising at least one of the foregoing catalysts.
Specific examples of alkali metal compounds or alkaline earth metal compounds include organic acid salts, inorganic acid salts, oxides, hydroxides, hydrides, and alcoholates of alkali metals and alkaline earth metals. In some embodiments, the catalyst is an alkali metal compound of the formula M1 X1, wherein M1 is selected from the group consisting of lithium, sodium, and potassium; and X1 is selected from the group consisting of hydroxide and OAr, wherein Ar is a monovalent aromatic radical.
More specifically, examples of alkali metal compounds include, but are not limited to, sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium bicarbonate, potassium bicarbonate, lithium bicarbonate, sodium carbonate, potassium carbonate, lithium carbonate, sodium acetate, potassium acetate, lithium acetate, lithium stearate, sodium stearate, potassium stearate, lithium hydroxyborate, sodium hydroxyborate, sodium phenoxyborate, sodium benzoate, potassium benzoate, lithium benzoate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, dilithium hydrogen phosphate, disodium salts, dipotassium salts, and dilithium salts of bisphenol A, and sodium salts, potassium salts, and lithium salts of phenol, etc.
Furthermore, specific examples of alkaline earth metal compounds include, but are not limited to, calcium hydroxide, barium hydroxide, magnesium hydroxide, strontium hydroxide, calcium bicarbonate, barium bicarbonate, magnesium bicarbonate, strontium bicarbonate, calcium carbonate, barium carbonate, magnesium carbonate, strontium carbonate, calcium acetate, barium acetate, magnesium acetate, strontium acetate, and strontium stearate, etc.
In other embodiments, the catalyst is a tetraorganoammonium compound of the formula R4 NY2, wherein R is a C1-C4 alkyl group, and Y2 is hydroxide, acetate, or OAr, wherein Ar is a monovalent aromatic radical. In still other embodiments, the catalyst is a tetraorganophosphonium compound of the formula R4 PY2, wherein R is a C1-C4 alkyl group, and Y2 is hydroxide, acetate, or OAr, wherein Ar is a monovalent aromatic radical.
Specific examples of tetraorganoammonium compounds and tetraorganophosphonium compounds include, but are not limited to tetramethylammonium hydroxide, tetrabutylammonium hydroxide, tetraethylphosphonium hydroxide, tetrabutylphosphonium acetate, tetrabutylphosphonium hydroxide and the like.
Any of the catalysts disclosed above may be used as combinations of 2 or more substances. The catalyst may be added in a variety of forms. The catalyst may be added as a solid, for example as a powder, or it may be dissolved in a solvent, for example, in water or alcohol.
In the present disclosure, the total catalyst composition is in one embodiment, in the amount of from about 1xc3x9710xe2x88x927 to about 2xc3x9710xe2x88x923 moles, and in another embodiment, from about 1xc3x9710xe2x88x926 to about 4xc3x9710xe2x88x924 moles for each mole of the combination of the bisphenol aromatic dihydroxy compound comonomer and the dicarboxylic acid diester.
The term melt polymerization is generally meant to refer to the polymerization process whereby the bisphenols, e.g., formulas (I) or (II) as shown below, 
aromatic dihydroxy compound comonomers of formula (V), dicarboxylic acid diesters of formula (X), and carbonic acid diesters of formula (XVI) condense in the presence of a suitable catalyst as described above. Melt polymerization can be accomplished in a process involving one or more stages. The one stage process comprises manufacturing polycarbonates by melt polycondensation of the above bis(hydroxyaryl) cyclohexanes, aromatic dihydroxy compound comonomers (III), dicarboxylic acid diesters, and carbonic acid diesters in the presence of the catalysts described above. The reactor employed for carrying out these polymerizations is not particularly in some embodiments, it can be made either of glass or a metal. In some embodiments, the reactor walls may be passivated by treatment with a suitable acidic material. If it is desirable to carry out the polymerization in a glass reactor, soaking it in an aqueous acid medium passivates the walls of the reactor. In various embodiments, the acids for this passivation process include water solutions of mineral acids, such as hydrochloric acid, sulfuric acid, nitric acid, and the like, and organic acids, such as acetic acid, methanesulfonic acid, toluenesulfonic acid, and the like.
In various embodiments, the reactants for the polymerization reaction can be charged into a reactor either in the solid form or in the molten form. Initial charging of reactants into a reactor and subsequent mixing of these materials under reactive conditions for the polymerization may be conducted in an inert gas atmosphere such as a nitrogen atmosphere. Mixing of the reaction mixture is accomplished by methods known in the art, such as by stirring. Reactive conditions in the present context refer to conditions comprising time, temperature, pressure and other factors that result in polymerization of the reactants.
In various embodiments, the polymerization is conducted by subjecting the above reaction mixture to a series of temperature-pressure-time protocols. In some embodiments, this involves gradually raising the reaction temperature in stages while gradually lowering the pressure in stages. Thus in various embodiments of this process, the pressure is varied from about atmospheric pressure at the start of the reaction to a value in a range of, in one embodiment, between about atmospheric pressure and about 0.01 millibar pressure; in another embodiment, between about atmospheric pressure and about 0.05 millibar pressure; and in another embodiment, between about 300 millibars pressure and about 0.05 millibar pressure. In various embodiments, the temperature is varied in the range between about the melting temperature of the reaction mixture and about 350xc2x0 C., between about 180xc2x0 C. and about 230xc2x0 C., between about 230xc2x0 C. and about 270xc2x0 C., and between about 270xc2x0 C. and about 350xc2x0 C. This procedure will generally ensure that the reactants react properly to give polyestercarbonates with the desired molecular weight, glass transition temperature and physical properties. The reaction proceeds to build the polymer chain with production of phenol by-product. Efficient removal of the phenol by-product by application of vacuum produces polyestercarbonates of high molecular weight. If phenol is not removed efficiently, it may participate in the backward reaction whereby the polymer chain is cleaved by phenol in the presence of the polymerization catalyst, thus leading to polymer of lower molecular weight with inferior mechanical and other physical properties. In various embodiments, the progress of the reaction may be monitored by measuring the melt viscosity or the weight average molecular weight of the reaction mixture. After the desired melt viscosity and/or molecular weight is reached, the final polyestercarbonate product may be isolated from the reactor in a solid or molten form.
The method of producing polyestercarbonates of the present disclosure is not limited to what is described hereinabove. Thus the process can be operated either in a batch, semi-batch, or a continuous mode. Reaction apparatus known in the art may be used in conducting this reaction, and in some embodiments, may be a horizontal type, tube type, or column type.
Polyestercarbonates prepared in the manner described above have a weight average molecular weight of at least about 5,000, a glass transition temperature of at least about 100xc2x0 C., and a dimensional stability in films comprising said polyestercarbonate, as measured by percentage elongation of less than about 0.05% relative to its initial length following exposure to nitrogen with a relative humidity of about 100%, at a temperature of about 23xc2x0 C., and for a duration of about 3 hours.
Dimensional stability of polyestercarbonates may be measured by placing a polyestercarbonate film in a controlled chamber and exposing it to a stream of nitrogen maintained at a pre-determined level of humidity and temperature for a specified length of time. The absorption of moisture by the polyestercarbonate sample will cause the film to swell or elongate. The film is then de-swelled by driving the absorbed moisture out using de-humidified heated nitrogen, and, the process is generally repeated to arrive at the percent elongation. In one aspect of this method, the process described above can be repeated more than once, and in some embodiments, three times to arrive at the percent elongation. A low percent elongation is indicative of an outstanding resistance to moisture absorption, which translates to excellent dimensional stability.
Polyestercarbonate films cast from polymer produced by the method of the present disclosure exhibit outstanding dimensional stability in a humid environment, as evidenced by the very low percent elongation of less than about 0.05% of the original length of the film. These materials exhibit much better dimensional stability compared to films made from a reference material, BPA homopolycarbonate and the comparative materials, a polycarbonate copolymer prepared from an interfacial reaction of a 45:55 mole ratio of the monomers, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane and 4,4xe2x80x2-(m-phenylenediisopropylidene) diphenol, respectively, with phosgene, and a homopolycarbonate derived from reaction of dimethylbisphenol cyclohexanone (DMBPC) with diphenyl carbonate.
The polyestercarbonates and the melt transesterification polymerization method for producing these polyestercarbonates, are useful for producing articles suitable for optical media applications. Preparation of such polycarbonates may be done by selection of catalyst, process conditions, and the proper proportion of the bisphenols, aromatic dihydroxy compound comonomers and dicarboxylic acid diesters. Choosing these parameters is within the ability of one skilled in the art with only minimal experimentation.
In various embodiments, the polyestercarbonates for making articles suitable for optical media applications comprise those in which the bisphenol is at least one bis (hydroxyaryl)cyclohexane described herein, the aromatic dihydroxy compound comonomer is at least one of BPA, resorcinol, bispded, and s-BPA, and the dicarboxylic acid diester is at least one selected from the group as shown in formula (X) 
wherein Y is a linear alkylidene group having the formula (CH2), where n has values in the range from about 4 to about 18, and Rxe2x80x2 is phenyl.
The polyestercarbonates compositions and the methods described above to prepare them are used to make optical articles and films for display devices. Optical articles that can be prepared using the polyestercarbonates comprise a film, an optical data storage medium, a rewritable optical disk, and a substrate for an optical data storage medium. The optical articles can function as the protective, transparent layer that covers the various recording media, such as high-density data storage using DVD, and more specifically, HDDVD, DVR, DVDxe2x88x92R and DVR+R, and DVDxe2x88x92RW and DVD+RW formats.
Display panel film is a key component of display panel devices. The material requirements for such a film includes good processibility, high molecular weight (e.g., an average molecular weight greater than about 5,000), and a glass transition temperature sufficient to withstand the heat generated during the display (e.g., generally greater than about 100xc2x0 C.). The various embodiments of the polyestercarbonates and methods of preparing them provide a means to produce materials that meet and exceed these requirements of high molecular weight, high glass transition temperatures, and good processibility, thus making them useful to produce such films for the display devices. These films can be cast from solutions of the polyestercarbonates prepared using the methods described hereinabove. Such films produced from this and other techniques known in the art possess good processibility, outstanding dimensional stability, and a glass transition temperature sufficient to withstand the heat generated during the display.
Another aspect of the present disclosure is a method of making an article comprising molding a composition comprising the polyestercarbonates produced by the melt transesterification polymerization methods described above. In various embodiments, the polyestercarbonates for the molding composition comprise those in which the bisphenol comprises the bis(hydroxyaryl)cyclohexane described herein.
The molding step for making such articles can be performed by injection molding, thermoforming, blow molding, and the like.